This invention relates to a sealing member incorporated in an orbital or rotary motor such as an engine, pump, or compressor. The sealing member is incorporated in the engine to provide a seal between the radial end face of the housing and the opposed radial end face of the piston or like member which orbits or rotates within the housing.
In order to allow the orbital or rotary movement of the piston member, within the housing, under a range of temperature and/or pressure conditions, such as may exist in an internal combustion engine, clearance must be provided between the radial end faces of the piston and housing to accommodate differential expansion between the piston member and housing.
Clearance also exists between the radial end faces of the piston member and housing to permit the required orbital or rotary movement therebetween and as a result of manufacturing tolerance.
However for the effective operation of the engine pump or compressor it is inherent that gas or fluid must be prevented from passing between these radial faces by way of the clearance provided, and thus a seal arrangement must be provided which will prevent the leakage of gas or fluids, whilst at the same time not interfering with the relative movement between the piston member and housing.
A large number of known orbital or rotary motors are provided with a number of van members which co-operate with the piston member and housing to form a number of chambers which vary in volume in sequence as the piston member rotates or orbits within the housing. In such motors it is also necessary to provide an effective seal against the passage of gas or fluid from one chamber to the adjacent chamber, between the radial faces of the piston member and housing.
In known engines it is customary to employ an annular sealing ring mounted in a groove in the radial face of the piston member concentric with the axis of the piston member. A spring device is disposed in the base of the groove holding the ring to urge the sealing ring into contact with the radial face of the housing and thus provide the desired seal.